However you will need a good GPS to find Steve, but once you arrive and through two secret unmarked doors your eyes will get really big. There are some secret projects that will dazzle you.

I learned the following about the tubes for the ZP3,

The first tube slot at the front in the most important tube, it is the input tube running in stereo from one tube.

The second slot for the 12ax7 tube is the output tube. This tube does NOT need to match the input tube, it may be an entirely different brand (this will drive me a little crazy, because I like to tube roll, and I have a bunch of single 12ax7 tubes sitting around).

The third slot for a 12au7 is a tube buffer and must be a 12au7.

I am now trying a RCA 5814a Triple Mica Blackplate in the 12au7 slot. It would distort after it warmed up. I found a solution, I replaced the OA3 with a OB3 (Steve tells me it lowers the amount of output as you go from OA3 to OD3). It seems the OA3 over powered the 5814a tube.

....you learn something every day !Cheers P K, I have an old Tung-Sol 12ax7 which was looking for a partner, now I can prise one of my Sylvania x3 micas out ( either one ! ) and see how the Tung-Sol performs.

I have been running a RCA Blk PL Triple Mica 5814A for quite a while and haven't had any problem with distortion. I've used it with 12AX7s and 5751's of various Brands while using an OA3 and 5Y3G rectifier...both RCA.

Now, knowing that the one and two position 12AX7 spots are independent of each other, the number of possible combinations to be explored has dramatically increased...Tube rolling Hell! or is it Heaven?! Mark.

"The man that hath no music in himself, nor is not moved with the concord of sweet sounds, is fit for treasons, deceptions, and spoils;The motions of his spirit are dull as night and his affections dark as Hell. Let no such man be trusted." William Shakespeare

Peter, In the past I had distortion with the ZP3...I forget with what tubes but when I changed the rectifiers in the Torii MK IV from RCA 5Y3GTs to RCA 5U4GBs the distortion was mostly resolved. Now I'm using Ken Rad WWII 5U4Gs and don't have problems with noise or distortion. Since you have had problems with tubes in both the 12AU7 and 12AX7 spots, you might want to consider tube changes in your Amp or the rectifier in your ZP3. I would hate to think you'll miss out on using 5751s or 5814s when it could be another tube causing the problem. Mark.

"The man that hath no music in himself, nor is not moved with the concord of sweet sounds, is fit for treasons, deceptions, and spoils;The motions of his spirit are dull as night and his affections dark as Hell. Let no such man be trusted." William Shakespeare

"The man that hath no music in himself, nor is not moved with the concord of sweet sounds, is fit for treasons, deceptions, and spoils;The motions of his spirit are dull as night and his affections dark as Hell. Let no such man be trusted." William Shakespeare

I have gone to an EZ80 (Bugle Boy Made for Amperex by Mullard?) in my Mini Torii, along with an OA2 in the OC2 slot, these changes, along with Mazda 6V6GT (Military from the 1950's) have made the ZP3 very very smooth.

I put the nos Tung-Sol 12ax7a in the first slot, Sylv x3 mic 2nd and a Mullard longplate 12au7 and the Tung-Sol made the treble become very detailed. So much so that poor old Peter Gabriels esses became sibilant and splashy on a Genisis album. Sounded funny. That was the only album it happened on and I got rather took with the extra detail with no loss anywhere else. Next day it all sounded balanced and ok.Now I`ve swapped the 1 and 2 positions around and like it better..I think.Well, enough so that I think I`m sorted for a good while.I played Santana Abraxas earlier today with a touch more volume and Santanas guitar sounded like it had a bit of snarl I hadn`t noticed before.

I have talked to Steve about 5751 tubes for my ZP3 a few weeks ago. He said that the specs are o.k., so these tubes are an alternative!I use in the first and second slot a NOS Tung Sol 5751 (grey plate) with really good results (well balanced, holographic, not too bright). They produce a much more involving music than the Teles 12AX7 (I tried ribbed and smooth plates)In the third slot, I use a Telefunken smooth plate 12AU7. (good tube, but after your experiences I will try a RCA Triple Mica 5814A)My rectifier tube is a Brimar 5Z4GY (very detailed)

I am really happy with my combo! I never thought that tubes in a pre phono stage could change the soul of music so deeply.